The most valuable drive in a spares cage is the one that restores a section without a commissioning laptop. The 2XH60-5AB0 build of the SINAMICS G115D is that unit for 0.55 kW sections running on hardwired I/O: local control, local/remote switching, integrated 24 V PSU, and a housing that matches every other 2XH6x build on the line.

What makes this build the low-risk spare?

Nothing on it depends on the network. A technician unbolts the failed unit, lands the gland power wiring and the local I/O harness, and the section runs — 1.7 A rated in LO duty, 3.4 A in HO, 200% for 3 s on starts, sensorless vector control already in the default parameter set. There is no device name to assign, no master list to update, no configuration file to restore, because there is no fieldbus stack in the order number.

When does the local-I/O choice reach its limit?

When the section starts reporting upward — energy data, diagnostics, line synchronisation all need the fieldbus builds (5AA0 for AS-Interface, 5AF0 for PROFINET), and those share the exact same 380 x 216 x 129 mm IP65/66 housing and ratings. Until that day, the 5AB0 keeps the standalone sections running and the spares shelf simple: one mechanical unit, two cable entries, zero network dependencies.